Railway block-signal apparatus.



No. 785,891. PATENTED MAR. 28, 1905. A. B KENDALL.

RAILWAY BLOCK SIGNAL APPARATUS.

APPLICATION FILED 001111904 tact-pieces have been fused together.

UNITED STATES Patented March 28, 1905.

PATENT OFFICE.

ALLEN BURTON KENDALL, OF MAYIVOOD, ILLINOIS.

SPECIFICATION forming part of Letters Patent No. 785,891, dated March 28, 1905.

Application filed October 17, 1904, Serial No. 228,797.

To all whom it may concern.-

Be it known that I, ALLEN BURTON KEN- DALL, a citizen of the United States, residing in Maywood, in the county of (look and State of Illinois, have invented a new and useful Improvement in Railway Block-Signal Apparatus, of which the following is a specification.

My invention relates to improvements in railway block-signal apparatus.

Heretofore in railway block-signal apparatus the signaling or controlling relay contacts have ordinarily been made by one or more light springmetal contact pieces, usually platinum, engaging a stationary contact-piece, and diiiiculties have heretofore been experienced in the practical operation of such signal apparatus owing to the liability of the opposing metal contact-pieces being fused together by electrical storms or other electric disturbances liable to occur where a street-car trolley-line crosses the railwaytrack, thus resulting in a failure of the signal apparatus to operate and consequent danger of wrecking trains or failure of the signal apparatus to show that the track is clear, thus unnecessarily disarranging the movement of trains.

The object of my invention is to provide a railway block-signal apparatus of a simple arrangement and construction'by means of which these difliculties and objections may be entirely overcome.

My invention consists in the means I employ to practically accomplish this object or resul ttl1at is to say, it consists, in connection with a block-signal apparatus or system of anysuitable kind, construction, or arrangement and having the customary metal contact- -pieces for the controlling or signaling relays of the system, of a supplemental mercury connection which connects with a loose metal contact-piece of the metallic connection, so that in case this loose metallic connection or contact-piece fuses with its cooperating metal contact-piece the electric circuit may still be made or broken as required at the mercury connection after the two opposing metal cony this means all danger or possibility of the signal apparatus failing to properly operate by reason of the fusion, sticking, or freezing together of the metallic contact-pieces is entirely overcome and the signal system made safe, reliable, and certain in operation.

My invention also consists in the novel construction of parts and devices and in the novel combinations of parts and devices herein shown or described.

In the accompanying drawings, forming a part of this specification, Figure 1 is a diagram view of a block-signal system of simple and contracted form provided with my invention. Fig. 2 is a detail sectional view showing the construction of one of my improved relay contacts or connections. Fig. 3 is a side elevation, partly in section. Figs. 4: and 5 illustrate a modification wherein the light spring-metal contact-pieces are made the movable member and the mercury contact-piece is made the stationary member.

In the drawings, A A represent the rails of a railway-track.

B represents an old and well-known form of disk style of railway signal device cus tomarily now employed on railways in blocksignalapparatus.

C and C are the signal line-wires supported on the cross-arms G of the telegraph-pole line C C" is the signal-battery included in the circuit C C.

D D are the relay instruments, the same being in connection with the several block track-circuits (Z. Each of the track-circuits (Z includes a battery (Z.

' As represented in the drawings, the signalcircuit C C is normally closed through the metal contact-pieces F F on relays D. The contact-piece F is preferably of light spring metal and should be made either of platinum or furnished with a platinumcontact-surface f. The contact-piece F is preferably double and shaped, preferably, aboutas shown in the drawings. The metal contact-piece F is a loose piece of metal or loosely connected to its support, so that in case it becomes fused with the contact-piece F it will not prevent or interfere with the operation of the relay or the movement of the relay-armature from which one or the other of the two contact- ICC pieces F F receives movement. This metal as the stationary member and the mercury contact-piece F may be made of any suitable and metal contact F as the normally movable metal but its upper portion, which contacts directly with the metal contact-piece F,is preferably of aluminium f and provided with a platinum engaging surface or portion f and its lower portion, which contacts with the mercury C, is preferablyof brass, steel, nickel, or aluminium and furnished with a silver or platinum contact-surface f. The mercury-containing vessel Gr is preferably a small bulb of glass and provided with asmall hole g at its upper portion, through which the stem of the loose metal contact-piece F passes. The head portion of the loose metal contact-piece F serves as acap to close this opening in the mercury vessel G. The glass mercury vessel G is connected to the electric connection H. which forms part of the signal-circuit C G, by a metal pin it, havinga head /t, which fits inside and seals the lower opening 9 in the mercury Vessel G and forms an electric connection between the connection H and the mercury (at in the vessel G. As illustrated in Figs. 1, 2, and 3, the electric connection H is movable and attached to the armature of the relay, from which it is also insulated, as is customary. As illustrated in the modification Fig. 5, the connection H is stationary and the contactpieces F are movable and connected with the armature.

The loose metal contact-piece F remains normally in electricconnection with the mercury G; but when for any cause the loose metal contact-piece F becomes fused to its cooperating metal contact-piece F then the contact-piece F really becomes a part of the contact-piece F, and the circuit is made and broken at the mercury connection. As in my invention the making and breaking of the circuit at the mercury connection only takes place when something is wrong with the making and breaking of the circuit at the metal contact-pieces F F, consequently no sparking occurs at the mercury connection except during the rare intervals when the apparatus would be inoperative except for the addition of this mercury connection, and though the mercury connection if it were in constant use for making and breaking the circuit in the normal operation of the signal apparatus would after a time oxidize and deteriorate and become unreliable and destroyed it nevertheless in my invention is durable, safe, and reliable, for the reason that the circuit is normally not made or broken at the mercury connection, so that the mercury is normally not subject to oxidization from the sparking incident to the making and breaking of the circuit.

While in the figures of the drawings 1, 2, and 3 I have illustrated the metal contact F member, it will be understood by those skilled in the art that this may be reversed and the mercury vessel attached to the stationary frame instead of connected to the movable armature.

I claim 1. In a block railway signal apparatus or system, the combination with the signaling or controlling relays and the signal-circuit, each of said relays having a metal contact-piece and an opposing loose metal contact-piece, and a mercury connection normally in connection with said loose metal contact-piece, whereby the fusing or freezing of said metal contactpieces together is prevented from interfering with the normal operation of the signal system or apparatus, substantially as specified.

2. In a block railway signal system or apparatus, the combination with the signal-circuit, of a metal contact-piece, an opposing loose metal contact-piece and a mercury connection with which said loose metal contactpiece is normally in connection whereby the signal-circuit may be closed and broken at the mercury connection when the metal contactpieces are fused or stuck together or in any manner made one, substantially as specified.

3. In a block railway signal system or apparatus, the combination with a signal-circuit, of a movable metal contact-piece, a normally stationary and loose metal contact-piece, and a stationary mercury connection normally in electric contact with said loose metal contactpiece, substantially as specified.

4:. The combination with a metal contactpiece, of a loose metal contact-piece, one movable in respect to the other for normally opening and closing the circuit and a mercury connection normally in contact with said loose metal contact-piece whereby the circuit may be closed and broken at the mercury connec tion when said" metal contact-pieces are fused or stuck together, or in any manner made one, substantially as specified.

5. The combination with a movable contactpiece, of a stationary loose contact-piece, said movable contact-piece and said loose contactpiece operating to normally open and close the circuit and a stationary mercury connection normally in electric contact with said loose metal contact-piece whereby the circuit may be closed and broken at the mercury connection when said movable and loose contactpieces are fused or stuck together or in any manner made one, substantially as specified.

ALLEN BURTON KENDALL.

Witnesses:

H. M. MUNDAY, EDMUND ADCOCK. 

